Yesterday afternoon, a Trump Organization spokesman confirmed that Donald Trump Jr. has hired a private attorney, Alan Futerfas, to represent his interests as the investigation into the Russia scandal continues. In light of the latest reporting from the New York Times, the decision to lawyer up was probably wise.

Before arranging a meeting with a Kremlin-connected Russian lawyer he believed would offer him compromising information about Hillary Clinton, Donald Trump Jr. was informed in an email that the material was part of a Russian government effort to aid his father's candidacy, according to three people with knowledge of the email.

The email to the younger Mr. Trump was sent by Rob Goldstone, a publicist and former British tabloid reporter who helped broker the June 2016 meeting.

For context, it's important to appreciate the evolution of the story in recent days. On Saturday night, the Timesfirst reported on Trump Jr. having met with a Kremlin-connected lawyer, Natalia Veselnitskaya, which the president's son said was a discussion about adoption policy. A day later, the story advanced: Trump Jr. acknowledged that he participated in the meeting because he hoped to acquire dirt on Hillary Clinton from the Russian attorney.

Trump was, in other words, effectively admitting that he tried to collude with a Russian national.

But this latest revelation is clearly the most dramatic to date. Trump Jr. was reportedly told, in writing, that the Russian government wanted to help elect his father -- at which point the Republican's son agreed to a meeting in order to collude with Moscow.

It's hard to overstate the significance of revelations like these. Dan Pfeiffer, a former top advisor in the Obama White House, noted overnight, "Not in the wildest Democratic fantasy did we think there would be an email to a Trump clearly stating a Russian government effort to help."

As the shockwave makes its way through the political world, there are multiple angles to keep in mind:

* Trump Jr. wasn't the only one from the campaign at that meeting. Remember, Jared Kushner, one of Trump's closest confidants, and Paul Manafort, the campaign chairman at the time, also participated in the June 2016 meeting at Trump Tower. They, too, will need to prepare an explanation.

* The Nixonian question: What did Donald Trump Sr. know and when did he know it? Three of the top people in Trump World attended this meeting, and no one said a word to the candidate?

* The sourcing: Much of the New York Times' reporting has been based on White House sourcing. It would appear someone in the West Wing isn't pleased with the president's oldest son.

* That Tapper interview: In July 2016, Trump Jr. did an interview with CNN's Jake Tapper, dismissing the idea that the Russians wanted to help the Republican campaign as a "phony" story. This looks even worse now.

* Congressional scrutiny: The investigation into the Trump-Russia scandal on Capitol Hill is ongoing, and yesterday, there was bipartisan interest in having a chat with Trump Jr. The latest revelations all but ensure that he will have to testify.

Stepping back, there's been ample talk in recent months about whether there's fire beneath the smoke in this controversy. But those questions have effectively been answered: Russia wanted to put Trump in power, and the Trump campaign welcomed the assistance of the foreign American adversary.

The question isn't whether there's fire; it's who'll be burned and how severely.